Electric heat shut-off for water heaters



Sept. 6, 1932. L. D. LOVEKIN I ELECTRIC HEAT SHUT-OFF FOR WATER HEATERS Filed Dec. 12, 1930 Patented Sept. 6, 1932 UNITED STATES LUTHER D. LOVEKIN, OF VILLA NOVA, PENNSYLVANIA ELECTRIC HEAT SHUT-OFF FOR WATER HEATERS Application filed December 12, 1930. Serial No. 501,930.

The principal object of the present invention is to provide for the employment of an electric circuit controller and circuit in a heat shut-off for water heaters so that in the case of Water heaters electrically heated, current may be interrupted through the heater. Another object of the invention is to construct and arrange the various parts of an electric heat shut-off for water heaters in the form of a complete portable device which can be variously applied, which is accurate and reliable in operation, and which can be readily taken 'gpart for effecting necessary renewals or recharging.

The invention will be claimed at the end hereof and, generally stated, the invention may be said to comprise an electric circuit controller, a weight slidably mounted to 0perate the controller, a thermally conducting water-tight casing adapted for immersion in the water of the heater, and a fusible metal plug arranged in the casing and supporting the weight which it permits to descend and operate the controller when the plug softens by heat.

The invention also comprises the improvements to be presently described and finally claimed.

be made to the accompanying drawing form.- ing part hereof and in which Figure 1 is a view, principally in central section, of an electric heat shut-off for Water heaters embodying features of the invention,

and

' Fig. 2 is a similar view of a portion of the device showing the parts in different position.

In the drawin 1 re resents a circuit con-' for immersion in the water of the water heat- 5 is a fusible metal plug arranged in the casing and supporting the weight 3 which it permits to descend and operate the controller when the plug softens by heat. As shown there is a spring 6 interposed between the contactor 2 and an insulating fitting 2', con- In the following description reference will nected with the weight 3, and its serves,when the weight is supported by the plug 5 to hold the'contactor 2 in good electrical contact with the contacts 7 and 8 of the circuit conductors 9 arranged through an insulating plug or socket 10 mounted in the top of the casing. Contactor 2 is shown as connected with the weight through a bolt 11 having a slight range of motion in respect to the weight and of which thehead is accommodated in space provided in the Weight. The plug 5 is mounted in a plug. 14 are means for adjusting the foot in respect to the weight.

The mode of operation of the described device may be explained as follows:

= In the position of the parts shown in Fig. 1, the path of current is closed at the circuit controller and the closed circuit path maintains', either directly or through relay devices,

in operation the means by which water is heated. These means are not shown because they are too well understood to require illustration or description. The water-tight casing 4 is exposed to the water of the heater either by including it in the hot or cold side connection of a-boiler or by arranging it to project into the interior of the boiler or otherwise as may be desired. As shown the casing 4 is arranged in the pipe fitting 1.5. When the water in which the casing 4 is immersed and which is the Water of the heater reaches a pre-determined temperature, the plug 5 softens and the foot 14 perforates it, dislodging a small disk of fusible material. The weight in dropping lowers the contactor 2 and interrupts the circuit, thus discontinuingthe heating action of the heater upon the water. In Fig. 2 the parts, or some of them,

are illustrated in the position last described. To reset the device the casing is separated,

asat 16, and the cartridge is left suspended on the foot 14 by the pin 16*. The casings 12 and 13 are separated and the parts of the fusible plug are removed and anew fusible plug inserted, whereupon the device is reassembled.

It will be obvious to those skilled in the art to which the invention relates that modifications may be made in details of construction and arrangement and matters of mere form without departing from the spirit of the invention which is not limited to such matters or otherwise than the prior art and the appended claims may require.

I claim:

1. An electric heat shut-01f for water heaters comprising, in combination, a circuit controller, a. weight slidably mounted to operate the circuit controller, a thermally conductive water-tight casing adapted for immersion in the water of the heater, and a fusible metal plug arranged in the casing and supporting the Weight which it permits to descend and operate the controller, when the plug softens by heat.

2. An electric heat shut-oif for water heaters comprising, in combination, a circuit controller including a contactor, a weight slidably mounted to operate the circuit controller,

a spring interposed between the contactor and weight to insure good contact, a thermally conductive water-tight casing adapted for immersion in the water of the heater, and

a fusible metal )lu arran ed in the casin 23 D and supporting the weight which it permits to descend and operate the controller, when the plug softens by heat.

8. An electric heat shut-off for water heaters comprising a thermally conductive casing adapted for immersion in water, a cartridge arranged in the casing and containing a fusible metal plug, a weight slidably mounted in the casing and having a foot supported by said plug, and a circuit controller carried by the casing and operated by the falling weight when the plug softens under heat.

4. An electric heat shut-off for water heaters comprising a water-tight casing, an insulating socket and its circuit connections mounted in the casing, a weight having an insulating fitting and free to slide in the casing, a bolt movable through the fitting and provided with a contactor, a spring interposed between the fitting and contactor, a foot adjustably connected with the weight, and a cartridge removably mounted in the casing and provided with a fusible metal plug upon which the foot rest-s;

LUTHER D. LOVEKIN. 

